1. Technical Field
The present disclosure relates generally to hardware for doors and other movable partitions. More particularly, the present disclosure relates to door locks including a cam having three lobes and to methods and systems including such door locks.
2. Background and Relevant Art
The Americans for Disabilities Act (ADA) and certain jurisdictions require certain hardware functions to ensure safe egress for the disabled from an office in the event of an emergency. Specifically, the ADA requires that hardware on accessible doors function without tight grasping, pinching, and/or twisting of the wrist. To allow for door lock operation without requiring a pinching action, some jurisdictions require a lever-shaped handle rather than a thumb latch. Furthermore, to allow for door lock operation without twisting of the wrist, some jurisdictions require a quarter turn to operate a lock rather than 360 degree (or more) rotation.
These requirements often bar the use of many typical door lock solutions. As such, these requirements often limit the choices available to designers for specifying hardware that is aesthetically appealing and consistent in appearance and function with other building hardware. For example, conventional locks that meet these requirements typically are aesthetically un-appealing and/or expensive. Furthermore, such conventional locks typically include complicated parts and/or installation procedures. In addition to the foregoing, conventional locks that meet these requirements are typically large and bulky. The size of such conventional locks often precludes them from use with thinner or narrow doors and partitions.
In particular, designers implementing resin-based or glass panels as doors or partitions may desire to mount the panel in a way that allows the panel to display its aesthetic properties. For instance, designers may desire to reduce the size and visibility of mounting hardware, such as a frame, supporting the panel. Unfortunately, many of the previously mentioned conventional locks are often too bulky or otherwise require the use of larger frames or mounting hardware.
For example, conventional locks may be thicker than desired, and thereby, require the designer to use a thicker panel or to use support hardware. Along similar lines, conventional locks may be wider than desired, and thereby, require extension into the edge of the panel or the use of wider supporting hardware. Such conventional locks may require modifications that are unsatisfactory to designers. For instance, the price of door panels is often proportional to the thickness, and thus, using thicker panels can increase the cost of the door or partition. Furthermore, using supporting hardware that is much thicker or wider than the panel, can adversely affect the aesthetics and/or structural integrity of the door.
Conventional MS-style locks are common, inexpensive, and thin enough for use with thinner doors. A typical MS style lock body includes a keyed mortise cylinder and a thumb turn mortise cylinder. Each of the mortise cylinders includes a single lobe cam that moves a pivoting locking mechanism between open and locked configurations upon rotation.
Unfortunately conventional MS-style locks do not meet all of the previously mentioned requirements. For example, conventional MS-style locks typically include a large free turning range where there is no activation of the locking mechanism. In other words, often times conventional MS-style locks require nearly 360 degrees of rotation of the thumb turn lever before the cam will engage the locking mechanism. Specifically, when the locking mechanism is activated from the keyed side (i.e., the outside of the door), the conventional MS style cam and the thumb turn lever on the inside of the door do not move with the keyed side. As a result, the thumb turn lever is not being in position to be immediately activated and requires an operator to rotate the thumb turn lever nearly 360 degrees before the cam engages the locking mechanism.
Accordingly, there are a number of disadvantages in conventional locks that can be addressed.